An interesting study by Dr. Otto Laske of the Interdevelopmental Institute  sought to determine if evidence-based coaching could increase ROI. This study followed the mental-emotional growth of six executives coached over a period of14 months. Dr. Laske posited that in the past, coaching was seen as part of the self-help movement and anecdotal evidence that it worked was acceptable. However, now organizations are looking for explicit proof of coaching effectiveness. One of the challenges with evaluating ROI is that changes in human behavior can take time, often an unpredictably long time. Another challenge is that developmental shifts are often nonlinear, occurring in stages. Dr. Laske’s approach to measuring ROI combined both facets to give not only a measurement of how many coachees improved but also an assessment of exactly how they improved in both behavioral changes and developmental shifts. In his study of the six executives, Dr. Laske’s findings showed all six improved to varying degrees, with three showing a large improvement.
The important methodological approaches to social science research include qualitative, quantitative, and a combination of the two. While quantitative analysis may seem superior to qualitative analysis, “quantitative data are more influenced by outside factors…Also, the appropriateness of quantitative or qualitative data depends on an evaluation’s purpose …”  Much of the research on coaching falls into the qualitative category. While the amount of research is increasing, it is still far behind the needs of a burgeoning coaching industry that wants to set appropriate standards on qualifications and process guidelines. While some of the research is produced by academics and their institutions, much of it is funded by private foundations, corporations, and professional associations.
Since the purpose of qualitative research is to gain an in-depth understanding of purposively selected participants from their perspective  this has been the most used type of research conducted in the field of coaching. Since this type of data is not easy to quantify, this method is usually used to report on themes and trends, instead of statistics. It is useful in emerging fields where few evaluative tools exist. As an example, the Boston University study consisted of interviews with over 75 executives in Fortune 100 companies, as well as interviews with 15 leading executive coaches.  This approach worked well with the subjective nature of exploring effectiveness. Themes involving the coaching experience were identified from which recommendations were developed. Another example of a good qualitative study is by Dr. Mary Wayne Bush who identified six key elements that are essential for effectiveness in executive coaching engagements based on themes that appeared during her interviews with 12 executives who had undergone successful coaching engagements. Download Article 1K Club